The paper established a risk assessment model on river water quality according to fuzzy theory,and determined the index weights of multiple monitoring sequences by using entropy method and gave 5 risk grades of water pollution.It also evaluated the risk of river pollutant sequence index and interval risk of water pollution in Shaanxi section of Weihe River.The results showed that water pollution risk in middle and downstream of Weihe River is larger and that in upper reaches is relatively lighter. The research provides basis for the control and recovery management of river water quality.